TV_ADD_DELTA
TV_ADD_DELTA(&ifd->ifnow_, pkt_time, &ifd->ifnow_);
TV_ADD_DELTA(nowp, ifd->maxiftime_, &ifd->ifnow_);
TV_ADD_DELTA(nowp, pkt_time, &ifd->ifnow_);
TV_ADD_DELTA(&ifd->ifnow_, pkt_time, &ifd->ifnow_);
TV_ADD_DELTA(nowp, pkt_time, &ifd->ifnow_);
TV_ADD_DELTA(nowp, tidle, &cl->undertime_);
TV_ADD_DELTA(&cl->undertime_, extradelay, &cl->undertime_);